Ophthalmoscope.



No. 845,099. PATENTED FEB. 26, 1907.

E. N. KLEIN.

OPHTHALMOSCOPE. APPLIUAT-I0N FILED JUNE 1a, 190e.

EMANUEL N. KLEIN, OF CINCINNATI, OHIO.

OFHTHALNIOSCOPE.

. Specification of Letters Patent.

Patented Feb. 26, 1907.

Application iled June 18, 1906. Serial No. 322,147.

To all Alf/c0111, it may concern:

Be it known that I, EMANUEL N. KLEIN, a citizen of the United States, residing at Oincinnati, IIanilton county, State of Ohio, have invented certain new and useful Imroveirents in Ophthalmoscopes; and I do declare the following to be a clear, full, and exact description thereof, attention being called to the accompanying drawings, with the reference characters marked thereon, which form also part of this speciflcation.

This invention relates to improvements in certain instruments usually employed by opticians and oculists for the purpose of examining the interior of the eye and generally known under the names of Ophthalmoscopes, fsliiascopes, or retinascopes They consist, substantially, of a reflector in form of a mirror, whereby light is thrown into the eye to illuminate the interior thereof to permit observation, which is through a small opening in said mirror. The intense action of light so reflected into the eye is quite trying in m ost cases, even in normal and healthy eyes, but more so in case of weak eyes or of sensitive ones or where disease of the retina exists. Satisfactory examination in such cases is very much interfered with and sometimes rendered impossible because of the unintentional twitching and movements of the patient due to the strong irritation, which causes also involuntary contraction of the pupil, which cannot be controlled. These disturbing e'dects are largely due to the presence of the ultra-violet rays of the light, which form also an element of the reflected light. The object of my invention is to counteract these disturbing effects as much as possible by rendering the reflected light non-irritating by revnoving therefrom the disturbing qualities of the same. This is done by acting more particularly upon the ultra-violet rays of the light, which I do by means of the mirror, so that they are prevented fron being reflected by the same into the eye. This I accomplish, substantially,by changing the light received by the mirror of the instrument by imparting to the sarne certain qualities, so that the objectionable elements of the light after received by the mirror are suppressed therein and not transnitted by it, For such purpose I use colored glass for the body of the mirror and particularly such of yellow color or of related shades and tints, like orange or amber, for instance. This color in particular is soothing for the eye and neutralizes the objectionable effects of the ultra-violet rays.

In the accompanying drawings I have illustrated my invention in connection with a customary plain ophthalmoscope or skiascope; but the same is of course applicable to all similar instruments involving the use of a mirror for the reflection of light into the eye.

In the drawings, Figure 1 is a front view, and Fig. 2 is a section, of the instrument.

A shows the mirror, and a the observationopening through the same. C is the casing, into which this mirror is set with the filmcovered side or reflecting-surface inside that is, next to the casing. c is an opening in the center of this latter, which registers with opening a in the mirror. This casing is attached to the handle B, by which the instrument is held to receive the light and whereby it is manipulated at the same time to reflect the light into the eye to be examined. This mirror A, as before stated, I make of a material which has qualities affecting the objectionable ultra-violet rays of the light in a manner that they form no part of the light which is reflected into the eye. The most preferable material for this purpose is glass having the color of yellow or its related tints, y

as before stated.

The disturbing elements-to wit, the rays mentioned-being neutralized and absorbed, and thereby prevented from reaching the interior of the eye, all irritating influences which interfere with a satisfactory examination are at once removed, and as a matter of fact the facilities for making a successful eX- amination are greatly enhanced, since only non-irritating light is now reflected into the e fe.

5 The pupil instead of involuntarily contracting as it did formerly in view of the irritating light remains large and rather dilates now under the influence of the soothing light, thus disclosing a larger area of the interior of the eye and increasing the field accessible for observation.

The removal of these objectionable elements from the light permits also use of larger mirrors and stronger lights, thus obtaining better results as heretofore possible.

Having described my invention, I clain as new- 1. An ophthalvnoscope or sinilar instrument provided with a reflecting-mirror which has qualities whereby the ultra-violet rays of IOO so as to be prevented from leaving,` the mirror low, und whereby the ultra-violet rays of this by reflection. light, received by the mirror are neutralized 2. An oplithalfnoseope or similar instruby absorption and prevented from bei-ng renient provided with e reliecting-inirror which .flected by the niirror.

is inode of glass Which is colored for the piir- Iii testimony whereof I hereunto aiiix my pose of acting upon certain elements of the signature in the presence of tWo Witnesses.

light, received by it7 to prevent suoli elements EMANUEL N. KLEIN.

the light received by tlie mirror are affected I is made of glass, having' a eolor Which is yelfrom leaving the mirror b y iellection. Witnesses:

3. An oplitlielinoseope or similar instru- C. SPENGEL, nient provided with a reflecting-mirror which T. LE BEAU. 

